Comparison of Ureteral Stents on Drainage Performance Under Extrinsic Compression

Triangular prismatic JJ stent does not cause more discomfort than tubular ones: a randomised controlled trial comparison

OBJECTIVE

To compare the stent-related symptoms (SRS) of three commonly used, readily accessible ureteric JJ stents after uncomplicated flexible ureteroscopic lithotripsy (FURL), in a prospective randomised controlled single-blind parallel-group study, in order to see whether structural difference might influence SRS.

PATIENTS AND METHODS

Patients undergoing FURL were randomised into three groups: the Cook Group received conventional 6 F Cook Universa Soft JJ stents as control, the Kang Yi Bo (KYB) Group received 6 F KYB anti-reflux JJ stents, and the Urovision Group received 7 F Urovision Visiostar ESWL JJ stents. The ureteric stent symptom questionnaire (USSQ) was administered at 1 week, 4 weeks (before stent removal), and 5 weeks (one week after stent removal as baseline evaluation) after stent insertion. Both raw and baseline-adjusted USSQ domain subscores at 1 week and 4 weeks were compared.

RESULTS

A total of 146 patients were included in the analysis. The KYB Group showed significantly lower P6&7 subscore yet higher urinary symptoms score 1 week and 4 weeks after stents insertion than both Cook and Urovision, whilst the Urovision Group achieved similar scores in most domains with Cook.

CONCLUSIONS

Although the KYB anti-reflux JJ stent might prevent vesicoureteral reflux, it induces significantly stronger urinary symptoms, both at 1 week or 4 weeks after stent insertion, with or without baseline correction. Despite the unique triangular prismatic shape, the Urovision Visiostar stent does not cause heavier urinary symptoms or pain compared to the conventional cylinder shape counterparts.

Unveiling the Challenges in Tandem Ureteral Stent Management for Malignant Ureteral Obstruction: Failure Rate, Risk Factors, and Durability of Their Replacement

BACKGROUND

Malignant ureteral obstruction (MUO) is a sequela of advanced malignant disease that requires renal drainage, with tandem ureteral stents (TUSs) being a viable option. This study aimed to evaluate the TUS failure rate, associated risk factors, and the feasibility of replacing failed TUSs with a new pair of stents.

METHODS

A retrospective analysis of MUO patients treated with TUS insertion from 2014 to 2022 was conducted. TUS failure was defined as urosepsis, recurrent urinary tract infections, acute kidney failure, or new hydronephrosis on imaging. Cox proportional hazard regression analysis identified the independent predictors of TUS failure.

RESULTS

A total of 240 procedures were performed on 186 patients, with TUS drainage failing in 67 patients (36%). The median time to failure was 7 months. Multivariate analysis revealed female gender (OR = 3.46, p = 0.002), pelvic mass (OR = 1.75, p = 0.001), and distal ureteral obstruction (OR = 2.27, p = 0.04) as significant risk factors for TUS failure. Of the failure group, 42 patients (22.6%) underwent TUS replacement for a new pair. Yet, 24 (57.2%) experienced a second failure, with a median time of 4.5 months. The risk factors for TUS second failure included a stricture longer than 30 mm (OR = 11.8, p = 0.04), replacement with TUSs of the same diameter (OR = 43, p = 0.003), and initial TUS failure within 6 months (OR = 19.2, p = 0.006).

CONCLUSIONS

TUS insertion for the treatment of MUO is feasible and has good outcomes with a relatively low failure rate. Primary pelvic mass and distal ureteral obstruction pose higher risks for TUS failure. Replacing failed TUSs with a new pair has a success rate of 42.8%. Consideration should be given to placing larger diameter stents when replacing failed TUS.